What Causes the Engine to Cut Out While Driving?
3 Answers
Causes and solutions for engine cut-out phenomenon: 1. Excessive or insufficient spark plug gap. A too-small gap weakens the spark and may cause carbon deposits to bridge the electrodes, preventing spark generation. An overly large gap increases the required breakdown voltage, overloading the ignition coil. When breakdown voltage exceeds the system's capacity, the spark plug fails to generate sparks, especially prone to misfiring at high speeds. Solution: Adjust spark plug gap. 2. Low fuel system pressure. Solution: Conduct fuel pressure testing. The gauge reading should match specifications in the vehicle manual. If pressure is too high, inspect the fuel pressure regulator; if too low, check the electric fuel pump, fuel filter, and pressure regulator. 3. Dirty fuel injectors causing unstable engine operation. Solution: Check fuel condition and perform engine air-fuel ratio testing.
Having driven many cars, I've noticed that sudden fuel cut-off during driving is quite common, usually related to the fuel system. The most frequent issue is a faulty fuel pump, which fails to deliver fuel from the tank to the engine, making the car suddenly lose power or even stall. Another common cause is a clogged fuel filter, obstructing the fuel line and affecting supply, often noticeable during hard acceleration. Additionally, a malfunctioning fuel pressure regulator can cause unstable fuel pressure, or loose/short-circuited wiring connections may lead to intermittent fuel pump operation. If the dashboard warning light is on, it could indicate a sensor or ECU (Engine Control Unit) problem. In such cases, first pull over safely to inspect, then visit a professional shop for diagnostic tools—avoid DIY fixes that might worsen the issue. Regularly pay attention to fuel quality; avoid low-grade gasoline that can cause deposits and clog components.
Speaking of sudden fuel cutoff while driving, let me share my experience. This situation is often caused by minor issues leading to major troubles, such as a clogged fuel filter or an overloaded fuel pump triggering protection shutdown, resulting in power loss. Another possibility is poor contact or burnout of the fuel pump relay—this part isn't expensive but crucial; once it fails, intermittent fuel supply issues may occur. Engine overheating could also be the culprit, as thermal protection might temporarily cut off fuel to safeguard components. During inspection, first check if there are any abnormal warning lights on the dashboard. If none are lit, try pressing the accelerator to see if the response feels sluggish. A cost-effective approach is to start with cheaper fixes, like replacing the filter, which usually costs around a hundred bucks—don't rush into dismantling the entire fuel tank. Cars are tools; maintaining them well can save you a lot of hassle.
